Hammer



FIG. 1 is a perspective view of a hammer;

FIG. 2 is a rear view of the hammer shown in FIG. 1;

FIG. 3 is a front view of the hammer shown in FIG. 1; and,

FIG. 4 is a right side view of the hammer shown in FIG. 1, the left side view being a mirror image thereof.

Features shown in broken lines illustrate portions of the hammer that form no part of the claimed design. 

CLAIM The ornamental design for a hammer, as shown and described. 